The QosDataTypes defined in the following chapters are used in the DatagramQos parameter in different datagram specific transport protocol mapping settings.

The DatagramQos contains an array of QosDataTypes. The array is null or empty if no QoS related parameters are set.

The DatagramQos parameter is always combined with a QosCategory parameter. Depending on the content of the QosCategory String, different elements need to be present within the DatagramQos array.

The specific processing of the QosCategory and DatagramQos content is described in 5.4.5.4.

Standard QosCategory values are defined in Table 103.

Table 103 – Standard QosCategory values

QosCategory	Description
Null or empty	This category indicates best-effort is used. DatagramQos shall be null or empty.
Opc.qos.cat://priority	This category indicates priority is used. DatagramQos shall contain one element of TransmitQosPriorityDataType or ReceiveQosPriorityDataType and optionally further elements which may be omitted.

This Structure DataType is an abstract base type for Structures with QoS related parameters. The QosDataType is formally defined in Table 104.

Table 104 – QosDataType structure

Name	Type	Description
QosDataType	Structure

The QosDataType Structure representation in the AddressSpace is defined in Table 105.

Table 105 – QosDataType definition

Attributes	Value
BrowseName	QosDataType
IsAbstract	True
Subtype of Structure defined in OPC 10000-5.
Conformance Units
PubSub Parameters QoS

This Structure DataType is an abstract base type for Structures with transmit QoS related parameters. The TransmitQosDataType is formally defined in Table 106.

Table 106 – TransmitQosDataType structure

Name	Type	Description
TransmitQosDataType	Structure

The TransmitQosDataType Structure representation in the AddressSpace is defined in Table 107.

Table 107 – TransmitQosDataType definition

Attributes	Value
BrowseName	TransmitQosDataType
IsAbstract	True
Subtype of QosDataType defined in 6.4.1.1.2.
Conformance Units
PubSub Parameters QoS

The PriorityLabel with DataType String specifies the priority of the according sender. The network stack will use the PriorityLabel to look up the priority settings for the transport protocol headers.

The priority labels defined by OPC UA should have the following form:

opc.qos.lbl://<label>

Example values are “opc.qos.lbl://low” or “opc.qos.lbl://high”. The mapping is described in 5.4.5.4.

Note: This version does not define concrete labels. The engineering process needs to provide them and also build up the PriorityMappingTable in OPC 10000-22 accordingly.

This Structure DataType is used to represent the priority lable specific transmit QoS parameters. It is a subtype of the TransmitQosDataType defined in 6.4.1.1.3.

The TransmitQosPriorityDataType is formally defined in Table 108.

Table 108 – TransmitQosPriorityDataType structure

Name	Type	Description
TransmitQosPriorityDataType	Structure	Subtype of TransmitQosDataType defined in 6.4.1.1.3.
PriorityLabel	String	Defined in 6.4.1.1.4.1.

Its representation in the AddressSpace is defined in Table 109.

Table 109 – TransmitQosPriorityDataType definition

Attributes	Value
BrowseName	TransmitQosPriorityDataType
IsAbstract	False
Subtype of TransmitQosDataType defined in 6.4.1.1.3.
Conformance Units
PubSub Parameters QoS

This Structure DataType is an abstract base type for Structures with receive QoS related parameters. The ReceiveQosDataType is formally defined in Table 110.

Table 110 – ReceiveQosDataType structure

Name	Type	Description
ReceiveQosDataType	Structure

The ReceiveQosDataType Structure representation in the AddressSpace is defined in Table 111.

Table 111 – ReceiveQosDataType definition

Attributes	Value
BrowseName	ReceiveQosDataType
IsAbstract	True
Subtype of QosDataType defined in 6.4.1.1.2.
Conformance Units
PubSub Parameters QoS

The PriorityLabel with DataType String specifies the priority of the according sender.

Futher details are defined in 6.4.1.1.4.1.

This Structure DataType is used to represent the priority lable specific receive QoS parameters. It is a subtype of the ReceiveQosDataType defined in 6.4.1.1.5.

The ReceiveQosPriorityDataType is formally defined in Table 112.

Table 112 – TransmitQosPriorityDataType structure

Name	Type	Description
ReceiveQosPriorityDataType	Structure	Subtype of ReceiveQosDataType defined in 6.4.1.1.5.
PriorityLabel	String	Defined in 6.4.1.1.6.1.

Its representation in the AddressSpace is defined in Table 113.

Table 113 – ReceiveQosPriorityDataType definition

Attributes	Value
BrowseName	ReceiveQosPriorityDataType
IsAbstract	False
Subtype of ReceiveQosDataType defined in 6.4.1.1.5.
Conformance Units
PubSub Parameters QoS